Alarm



J. CRONAN.

ALARM.

APPLICATION FILED FEB. 2, 1920.

1,40 ,937, Pamnted Feb. 14, 1922.

2 SHEETSSHEET I.

cf Groncvrv J. CRONAN.

-ALARM.

Patented Feb. 14, 1922.

APPLICATION FILED FEB.2 1920.

2 SHEETS-SHEET 2.

Vil i fluucnl'ot- J1 dv'onaw JOSEPH CRONAN, OF ROSE GREEK, MINNESOTA.

ALARM.

Specification of Letters Patent.

Patented Feb. 14, 1922.

Application filed February 2, 1920. Serial No. 355,603.

To all whom it may concern Be it known that I, JOSEPH CRoNAN, a citizen of the United. States, residing at Rose Creek, in the county of Mower and State of Minnesota, have invented new and useful Improvements in Alarms, of which the following is a specification.

This invention relates to bearing alarms and the principal object of the invention is to provide means for giving an alarm when a bearing becomes hot from lack of lubricant or other reasons. 1

Another object of the invention is to provide means for adjusting the device so that the alarm will be sounded at any desired temperature.

Still another object of the invention is to provide means'w-hereby .a plurality of devices may be connected with a switch board located at a central point and provided with means for indicating which particular bearing is hot, so that a single operator may attend to the entire plant.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claims. V

In describing my invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which Figure 1 is a diagrammatic view showing my invention in use.

Figure 2 is an enlarged sectional view of one of the devices.

Figures 3 and 4 are detail views.

In these views 1 indicates a mercury reservoir which is provided with screw threads so that it may be inserted in a screw threaded socket in a bearing. 2 indicates a closing cap for said reservoir which has screw threaded engagement therewith. This cap is provided with a long neck 3, having a small bore 4. The upper part of said neck is provided with an expansionchamber 5. and the bore below said chamber is enlarged to receive a sleeve 6 of insulating material, preferably glass. The end of the neck is open and screw threaded to receive a screw threaded closing plug 7. This plug is pro vided with a screw threaded bore to receive the screw threaded part of a needle 8. The

upper end or" this needle is provided with a slot to receive a screw driver so that it may be adjusted in the plug. The point of the needle is adapted to lie in the sleeve 6, as shown. A look nut 9 holds the needle in adjusted position in the plug and a second nut 10 is adapted to hold one of the conductors betweenitself and said nut 9. The end of the other conductor is connected with the terminal 11 carried by the neck. A closing cap 12 is adapted to be placed over the end of the neck and to be suitably held on said neck. This cap is provided with an opening 13 through which the conductor passes. Both the neck and the reservoir are provided with wrench engaging portions, as shown at 14 and 14', so that these parts may be screwed home.

One of these devicesis placed in each of the bearings 15, as shown in Figure 1; and the needle of each device is connected by a conductor 16 with a terminal of a switch 17. These switches are located on a switch board 18 and each switch is in electrical connection with an indicating liamp 22 and alarm 19 and switch 20. This battery is also in electrical connection with the second terminal of each device.

Sufficient mercury is placed in each device to partly fill the bore of the neck as shown in Figure 2. As soon as the bearin becomes hot the mercury will expand an rise in said bore and enter the expansion chamber. As soon as it touches the needle the circult will be closed and thus sound the alarm and light the lamp in the switch board and thus notify the attendant that the bearing needs attention.

This invention is primarily intended to be used in mills and elevators where the danger of combustion is so great from overheated bearings, or hot boxes, as they are more commonly called, due to the dust which is ever, resent. However it can be used to great a$vantages on any bearing which runs at high speed or has a heavy load or is not under close personal attention.

Attention is called to the fact that the lower part of the needle is entirely surrounded by the lass insulator so that there is no danger of s ort circuits. Owing to the large amount of mercury in the device it is very sensitive and will not fail to operate. I prefer to make the point of the needle and the bottom of the mercury holder of noncorrosive metal so as to insure a positive contact and making the device practically free of internal trouble.

It is thought from the foregoing description that the advantagesand novel features of my invention will be readily apparent.

I desire it to be understood that I may make changes in the construction and inthe combination and arrangement of the several parts, provided that such changes fall within the .scope of the appended claim.

What I claim is A circuit closer for a bearing alarm comprisin a mercury reservoir adapted to be place in contact with bearing, a closing cap for-said reservoir pr vided with a long neck, a screw threaded plug'of insulated material closing the upper end of the neck, a needle adjustably carried by said plug and extending into the borr of the neck, a sleeve of insulating material .m the neck surrounding the lower end of the needle, said neck having an expansion chamber formed therein between the plug and sleeve, a cap engaging the upper end of the neck and enclosing the" plug and means on the needle and neck for attaching terminal wires of a circuit.

In testimony whereof I afiix my signature.

JOSEPH CRON AN. 

